


Things Change But Stay The Same

by Anonymous



Category: Supernatural
Genre: Alpha Dean Winchester, Alpha Sam Winchester, Alpha/Omega Dynamics, Angst, Bottom Castiel (Supernatural), Dominance And Claiming, Double Penetration, Hurt Castiel (Supernatural), Hurt Dean Winchester, M/M, Multi, Omega Castiel (Supernatural), Protective Castiel (Supernatural), Protective Dean Winchester, Protective Sam Winchester, WinCasWin
Language: English
Status: Completed
Published: 2019-04-03
Updated: 2019-04-03
Packaged: 2020-01-01 07:04:38
Rating: Mature
Warnings: Graphic Depictions Of Violence, Rape/Non-Con
Chapters: 1
Words: 2,132
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18331034
Author URL: https://archiveofourown.org/
Summary: Michael has transformed the world, somehow changing everyone so that they are now Alpha (mostly) or Omega (much rarer).The small family in the bunker is not immune, but has learned to adjust.When Cas enters his heat, he shuts himself away.  When either Winchester brother goes into rut, they leave for the duration.It works.  At least until their alpha tendencies start to take over; now the three of them have a choice to make, and it turns out to be what they wanted all along.





	Things Change But Stay The Same

**Author's Note:**

> There are no betas in this world; Michael changed everyone to either alpha or omega, and there are very few omegas and they are always at risk from predatory alphas sometimes with horrific consequences.
> 
> The rape/non con warning refers to the risk omegas face in general from alphas, but also to a previous off screen incident where Dean lost control and tried to force Cas but was prevented by Sam. The hurt comfort tags relate to this, and to a separate incident where Sam clashed with Dean and Dean’s arm was broken.
> 
> It’s a very dark world now that our guys are living in, where Cas can’t leave the bunker because he simply wouldn’t be safe.

There’s some smart-ass scientific name for it, for the way it feels like acid burning through your veins, for the way your adrenaline spikes so bad your heart rate doubles, for the way you feel like you could rend metal with your bare hands, but it’s flesh you’re gonna tear into, and…

Dean doesn’t give a flying fuck what it’s called. All he knows right then is that Sam might be his brother, but he’s going to kill him.

From the way Sam’s snarling and swiping at him, he’s got the same damn idea, but that’s too fucking bad, because only one of them is winning this fight, and it isn’t going to be that little _prick_ , it’s going to be…

Something grabs hold of him, a hand fists in his hair, and tugs him. Some other bastard wanting a piece of him, okay, _fine_ , they can have it if they want it so damn bad, he’ll take _any_ of them on, and he’s ready to lash out when whoever has hold of him yanks his head down, and his face touches skin.

A familiar scent fills his nostrils, and it’s like the sweetest thing he’s ever known. It feels like that lull between being awake and asleep, when you’re warm and relaxed and just ready to slip under.

The fight fades out of him, and he staggers back, body crashing hard after the Stag.

Cas looks caught halfway between being furious and being so damn scared, and that is not something his omega should ever be; nothing should get near enough to Cas to even cause him concern, but…

Sam snarls, and charges, eyes rimmed with red, and he’s too lost to his body chemistry to see who’s standing in between them.

Dean moves faster than he should be able to, and pushes Cas out of the way, lets Sam collide with him.

Like this, now, even with his body shaking, Dean still has the upper hand. Because he can think clearly, thanks to Cas, and Sam… Sam’s like a beast about to hit his rut, all teeth and claw and nothing going on upstairs.

That’s how Dean manages to flip him and pin him to the floor, and holds him there while Cas crowds in on him and lets Sam scent him, lets his presence calm the other alpha just like it did Dean.

It takes Sam a little longer to come around, always has, and afterwards they rest sitting against the wall, Cas between them, his presence, his scent, soothing away the last of the Stag until they’re fully themselves again.

++

Whatever Michael did, after escaping his own world, even the top scientists on Earth don’t seem to know.

They don’t even know that an archangel from another dimension is responsible; to them, it’s a virus, or a genetic anomaly caused by the amount of plastic swimming around in the oceans and in people’s bloodstreams, or a mutation designed to offset the increasingly poor fertility rates in both men and women around the world.

A few of the fringe religious groups proclaim it a judgement from God, and Dean could almost find it funny that the tin hat brigade are the ones closest to the truth.

Whatever everybody else wants to attribute it to, Dean doesn’t care. Nobody escapes it, not even them, so maybe it was some kind of disease after all, though they’ll probably never know.

Once it’s done, everybody’s different, and everything has changed.

++

There are three calendars on the wall in the bunker, one for each of them.

They track their ruts and heats scrupulously because they can’t afford not to. 

It was difficult in the beginning, there were mistakes and each of them got hurt more than once (he still remembers Sam breaking his arm one time with no warning at all; still remembers Sam hauling him off Cas and shoving him out of the room, and how Cas flinched around him for days after).

But they learned, and when it’s time for Cas’s heat, they double up on blockers and Cas showers four times a day and keeps his room door locked.

Because when whatever Michael did hit him too, it didn’t just turn him into an Omega.

It locked down his Grace, and as near as they can tell, that’s permanent.

But while they can control themselves during those times, it’s their ruts that are the worst.

A couple of days in advance, whichever one of them is about to cycle will head out to Rufus’s old cabin. It’s isolated enough that they don’t have to worry about running into another omega (hard enough, these past few months), or provoking a challenge from another alpha even if there’s no omega around to fight for.

The other one always stays with Cas, because it’s only with them, in the bunker, that Cas is safe.

Even outside of their heats, omegas’ scents give them away all the time. And there might be laws against kidnapping and rape, but Michael’s tinkering was a little unequal.

Less than one quarter of the population became omegas, and that doesn’t bode well for them or for the survival of the species.

So maybe that was Michael’s plan all along.

Anyway, that’s not the first time he or Sam have gone through the Stag, but it is the first time they’ve gone through it at the same time, with each other.

It nearly never happens outside of ruts, but it did today, and if Cas hadn’t been there…

But he was there, and being there almost got him hurt.

Dean can’t get the horror stories out of his head, about omegas being fought over like a piece of meat by packs of alphas, and by the time it’s over, and the alphas have come out of it, the omega’s dead, crushed, or torn apart.

That’s why Cas doesn’t leave the bunker; so he’ll be safe from that.

But maybe that’s a tactic that isn’t going to work anymore.

++

He knows Cas’s heat is near; the calendar aside, Cas smells sweeter, and he’s sleeping more, and showering more, so Dean knows he’s starting to slick.

He waits until he’s sure Cas is well under, and then tells Sam they need to talk.

He feels shitty doing this without Cas there, but this is something he and Sam have to settle between them first. There’s no point putting something this _out there_ to Cas only to find that Sam’s not on board with it.

It’s just…. If he isn’t, and things are going to get worse, then one of them will have to go, because Cas was at risk today, and that can’t happen again.

They’re all he has now, because even though he can fight, and he’s resourceful and he’s smart, there’s a billion alphas out there who won’t care about any of that.

This bunker is Cas’s sanctuary, his shelter.

They’re his alphas, and maybe…. Maybe it’s time to make that official.

++

Cas doesn’t say anything straight away, and that has Dean panicking inside even while he tries to project calm, and safety, and can feel Sam doing the same, because the last thing they need is Cas thinking they've both turned feral and they’re going to force him.

They would never, except Dean knows there’s been some close calls. Especially at the start, but that fight in the library, it wasn’t exactly a promising sign.

“You’d both be...satisfied...with that? With...sharing me?”

It shouldn’t be about what they’d be satisfied with, Dean knows it, but it doesn’t silence the sharp snarl inside him, that part that’s pure alpha, reacting to the thought of _sharing_.

But Dean is more than this. So is Sam. They both want Cas, they both love him, and Dean kind of figures they’d have found their way here eventually.

Michael just put them on the short road.

It’s not the same, but it’s not so different.

For them, anyway.

“We’ll make it work,” Sam says. He’s keeping his voice low, soft, knowing what soothes Cas. Even before he changed, he never liked it when they were upset in general, with each other, or with him.

Dean nods. “All that matters is that you’re safe, we’re together, we’re a family. And Cas…. Don’t you want to? Knowing that we can?”

He’s not talking about the drive all omegas have. It’s a different side of the same coin from alphas; omegas can be just as owned by their bodies as alphas can.

He’s talking about the fact that they have a chance here to really cement their family, as well as making sure Cas is safe from what happened to his alphas ever happening again.

Cas studies them for a moment, as if weighing up the situation, listing mentally all the pros and cons, considering problems they’ve probably never thought of, and ways to resolve them.

And then he nods.

“I’m at my most fertile in four days. If we’re going to try, it should be then.”

++

It isn’t like they haven’t scratched the surface of this.

Even before the change, Dean knows he felt something for Cas more than friendship or brotherhood. If he hadn’t been shackled by the fear of disappointing a father long gone, or by the need to put his responsibilities before himself every damn time, he might have done something sooner.

Something more than let his touch linger when he helped Cas up, or stitched his wounds when he bit off more than even an angel could chew, or hugged him after yet another close call.

And Sam…. Sam was also caught in Cas’s orbit, determined not to get pulled in any further (mainly, Dean realises, because Sam thought he and Cas were a thing, or would be) but not able to pull fully away.

Neither of them deserves to be shut out of this, and Cas deserves not to have to choose, unless he wants to.

He doesn’t; he favours their solution, an unorthodox family arrangement, but when has anything they’ve done been anything but?

All the same, they’ve never come this close, and Cas half joking worries about first night nerves, so decides the time they’re going to try and breed him (Dean hates that expression, accurate though it is) isn’t going to be their _first_ time.

And since they’ll be doing this together then, they can do it together now.

Not exactly the same way, but still.

It’s close enough, Dean thinks, as Cas lies between them, and they get used to touching him in ways they’ve always wanted to. 

They’re all nervous, but they scent Cas, and he scents them, and that helps, and when he comes Dean feels like this is going to work.

++

Being in heat means Cas is looser, his hole leaking, but he’s definitely not loose enough to take them both at the same time.

Sam holds Cas in his arms, soothing him, as Dean carefully works him open, getting him ready.

By the time he’s done, Cas is sweat slick and begging, but they need to know this is him talking, not his biology.

Cas cups his face, and stares at him, and maybe his Grace is bound away in there, but Dean sees the angel who strode into the barn that night, the angel who led an army into battle to save some wrecked soul from the worst Hell had to offer.

“Now,” Cas says, and in a tone that suggests they better not argue.

So they don’t. Sam helps Cas on to his knees, thighs spread wide for balance, one of them in front, and one behind, and Dean goes first, pressing in, feeling Cas’s body slowly yield to him.

Cas rests his forehead on Dean’s shoulder, grunting a little at the intrusion, but then going with it when Dean tucks him in a little closer, making it easier for Sam to get into position.

Feeling Sam search for room in there, waiting for Cas’s body to accept the double breach, it should feel like they’re crossing some kind of line here.

Except it doesn’t. If feels like they’ve finally arrived someplace they’ve been traveling a long way to get to, and then Cas’s body gives, and Sam slides in, and Cas is slick as Dean’s ever seen him, and he bears down, calling their names, and that’s it.

White hot heat bursts through Dean, and his alpha roars its satisfaction as he does what they all wanted, fills Cas up, knows Sam’s doing the same, and if they’re lucky, if they’re very, very lucky….

Nine months from now, there’ll be a fourth member to their family, and in the meantime, Cas is now finally, properly, their omega.

They’re his alphas. 

And everything is going to be okay.


End file.
